**20. CEA in the presence of contralateral occlusion**

Hemodynamically significant carotid stenoses are associated with 30% of early post-CABG strokes. The perioperative stroke risk is <2% when carotid stenoses are <50%, 10% when stenoses are 50% to 80%, 11% to 18.8% in patients with stenoses >80%. The risk shoots to 20% with untreated, bilateral, high-grade stenoses or an occluded carotid artery and contralateral

The majority of strokes happen after the first 24 hours post CABG. This suggests that majority of strokes cannot be simply be ascribed to an adverse intra-operative event (low flow, hypo‐ tension and carotid embolism). The overall case fatality following post-CABG stroke as 23.1%. [43]In real life, it is not possible to state how often carotid stenosis of any degree of severity contributes to the incidence of ischemic stroke after CABG. Naylor et al concluded that primary carotid thromboembolic disease alone was not responsible for up to 59% of post CABG strokes. A significant proportion of post-operative strokes was in the vertebro-basilar territory or located contralateral to the severely stenosed carotid or ipsilateral to an insignificant stenosis. Aortic arch atherosclerosis embolization may be an important cause of stroke in the majority

**1.** Staged approach: Advocates of a staged procedure perform CEA several days prior to CABG or several weeks following cardiac surgery. The rationale of the staged procedure is to decrease the risk of stroke in the cardiac procedure and eliminate the need for longer and more stressful combined procedure. Increased cardiac morbidity and mortality

In those with a history of TIA or stroke who have a significant carotid artery stenosis (50% to 99% in men or 70% to 99% in women), the likelihood of a post-CABG stroke is high; as a result, they are likely to benefit from carotid revascularization. Conversely, CABG alone can be performed safely in patients with asymptomatic unilateral carotid stenoses, because a carotid revascularization procedure offers no discernible reduction in the incidence of stroke or death in these individuals. Men with asymptomatic bilateral severe carotid stenoses (50% to 99%) or a unilateral severe stenosis in conjunction with a contralateral carotid artery occlusion may be considered for carotid revascularization in conjunction with CABG. Little evidence exists to suggest that women with asymptomatic carotid artery disease benefit from carotid revascu‐ larization in conjunction with CABG. Whether the carotid and coronary revascularization procedures are performed simultaneously or in a staged, sequential fashion is usually dictated by the presence or absence of certain clinical variables. In general, synchronous combined procedures are performed only in those with both cerebrovascular symptoms and ACS.[44] **2.** Combined approach: performing CEA and CABG in the same setting: If the combined approach can be done safely, a second surgical procedure and hospital stay may be eliminated, with significant cost reduction. Long-term stroke free survival may also be significantly improved.[42] The problem with this approach is that the stroke rate is

resulting from CEA may offset potential benefits of this approach.[42]

high-grade stenosis.[43]

118 Carotid Artery Disease - From Bench to Bedside and Beyond

of cases.[43]

**19. Approaches to treatment**

exceedingly high.

Patients with contralateral carotid occlusion have higher surgical risk for CEA due to multiple reasons; reduced collateral circulation during carotid clamping, cerebral hemorrhage secon‐ dary to hyperperfusion syndrome, and the overall advanced status of the vascular disease. Surgical mortality was extremely high in patients with a contralateral carotid occlusion and only 34% of the surgically treated patients were alive at 66 months in contrast to 63% of medically treated patients.(88) Results from the NASCET study demonstrated that medically treated patients with a contralateral occluded carotid were more than twice as likely to have a stroke compared to patients with a patent contralateral artery. However, when compared with medically treated patients, the overall risk of stroke contralateral to an occluded carotid artery was significantly reduced in the surgical patients. The risk of stroke in medically treated patients was 69% at 2 years versus 22% in patients treated surgically. (2) Thus, CEA with contralateral occlusion is a risky procedure but its risk may be justified considering the natural history of the disease.
